Question

我是MYSQL初学者，我遇到查询问题：

我有两张桌子（来电，来电失败）。

来电拥有这些列（called_number，duration）。
callsfailed 包含这些列（called_number，release_reason）

让我们说来电表是：

+---------------+----------+
| called_number | duration |
+---------------+----------+
| 1010101       | 13       |
| 1010101       | 18       |
| 1010101       | 20       |
| 2020202       | 50       |
| 2020202       | 20       |
| 3030303       | 10       |
| 4040404       | 30       |
+---------------+----------+

来电失败表格为：

+---------------+----------------+
| called_number | release_reason |
+---------------+----------------+
| 1010101       | -1             |
| 1010101       | -1             |
| 2020202       | -1             |
| 3030303       | 406            |
| 4040404       | 503            |
| 5050505       | -1             |
| 5050505       | -1             |
| 6060606       | -1             |
+---------------+----------------+

我想选择被叫号码＆gt; 1，当持续时间小于25时，或者它使release_reason = -1。超过1次。

但是如果caller_number的持续时间超过25，即使它有release_reason = -1，也不要选择它。

结果将是：

+---------------+-------+
| called_number | count |
+---------------+-------+
| 1010101       | 3     |
| 5050505       | 2     |
+---------------+-------+

我的代码是：

(  SELECT called_number, duration, COUNT(*) count 
   FROM calls 
   GROUP BY called_number 
   Having COUNT(called_number) > 1 and duration < 25 
) 

UNION 

( SELECT called_number, release_reason, COUNT(*) count 
  FROM callsfailed 
  GROUP BY called_number 
  Having COUNT(called_number) > 1 and release_reason = -1 
)

Answer 1

您可能正在寻找加入

  select t1.called_number, t1.duration,  t1.count 
  from 

  (  SELECT called_number, duration, COUNT(*) count 
     FROM calls 
     GROUP BY called_number 
     Having COUNT(called_number) > 1 and duration < 25 
  ) t1

  left join 

  ( SELECT called_number, release_reason, COUNT(*) count 
    FROM callsfailed 
    GROUP BY called_number 
    Having COUNT(called_number) > 1 and release_reason = -1 
  )  t2 on t1.called_number = t2.called_number

但是对于工会来说，你可能需要持续时间e release_reason

      SELECT called_number, duration, COUNT(*) count 
      FROM calls 
      WHERE duration < 25 
      GROUP BY called_number 
      Having COUNT(called_number) > 1 

      union 

      SELECT called_number, release_reason, COUNT(*) count 
      FROM callsfailed 
      GROUP BY called_number 
      where release_reason = -1 
      Having COUNT(called_number) > 1

Answer 2

问题上的差距很小。

在预期的结果中，1010101的计数不应该是5？
除了被叫号码之外，还有任何关系两个表中的条目？
您的代码获得所需结果的可能性非常低。

这是我对你想要实现的目标的最佳猜测

SELECT T1.called_number，（T1.C1 + T2.C2）AS count FROM（SELECT called_number，COUNT（）AS C1 FROM调用WHERE持续时间＆lt; 25 GROUP BY called_number）T1 JOIN（SELECT called_number，COUNT（）AS C2 FROM callsfailed WHERE release_reason = -1 GROUP BY called_number）T2 ON T1.called_number = T2.called_number WHERE（T1.C1 + T2.C2）＆gt; 1;

Answer 3

您可以将UNION用作派生表，并像这样选择

positive_threshold_0.500000_mean

你有结果

MYSQL（在一定条件下选择）

3 个答案: